Aircraft



A. K. PETERSON AIRCRAFT Marehl'l, 11931.

Filed Dec. 17, 1928 `Mardi 17, 1931.

A. K. PETERSON AIRCRAFT Filed Dec. 17, 1928 2 Sheets-Sheet 2 ff -El 5 QL f fl 3D za J4 54. Z5

fz 75' Z5 Patented Mar. 17, 1931 UNITED: STATES VPATENT OFFICE ALBIN K.PETERSON, F LOS ANGELES, CALIFORNTA, ASSIGNOR, BY MESNE ASSIGN- MENTS,TO JOSEPH KREUTZER CORPORATION, OF LOS ANGELES, CALIFORNIA, A

CORPORATION 0F NEVADA AIRCRAFT Application filed December 17, 1928.Serial No. 326,524.

This invention relates to motor powered aircrafts and one of theimportant objects of the invention is to increase the stability ofplural motored aircraft.

` Vhen motors are mounted in the well known manner on opposite sides ofthe longitudinal axis of an airplane, if one of the motors should stop,or be stopped, for any rean son, whatever inherent stability theairplane has when the motors on opposite sides are operating, isdetrimentally affected, since the propeller operating on one side tendsto turn the aircraft in a circle and, to avoid this tendency, it isnecessary to set the rudder at such an angle that the rudder will tendto turn cided variation in the line of flight and, ac-

cordingly, the Hight is quite jumpy or uneven and, more or less,dangerous. v

An important object of the present invention is to so mount the outboardmotors, that is to say the motors on either side of the longitudinalaxis of the aircraft, at an angle to the longitudinal axis of theaircraft, or so that they may be turned at an angle, in order that theslipstream of the propellers driven by said motors will be directedrearwardly and inwardly toward the opposite sides of the -fuselage andtoward the opposite sides of the rudder airfoil and vertical hn. Thus,if oneof the outboard `motors `should stop or be stopped, the otheroutboard motorwill drive the slipstream from its propeller against oneside of the fuselage andagainst oneside of the rudder and vertical finso as to Vcounteract thetendency to turning of the airplane in a circle.The angular position of the operating outboard motor also entails thatits propeller axis is directed forwardly away `from the side about whichthe aircraft would nat`urally tend to turn when the` other outboard mo-Ator is not operating, thus tending to pull the Y lnose of the aircraftin a direction opposite to that in which it` would drift, if the turningaxis of the propeller were parallel to the lon- `gitudinal axis of theaircraft.

It will be readily understood that the invention may be embodied inaircraft provided with two or more propellers, of which at least two arepositioned on opposite sides of the longitudinal axis of the aircraft.

Another important object is to mount the motors and their propeller-s sothat the path ofrotation of the propeller blade tips will besubstantially below the upper or vacuum face of the wing airfoils. Iterm the upper face of the wing airfoil vacuum face because of the wellknown fact that a partial vacuum or lowered pressure is created abovethe Wing as compared with the pressure below said wing. By insuringthatthe slipstream of the propellers flows rearwardly beneath the wingairfoil, the partial vacuum created above said airfoil is not disturbedor reduced 1n degree by the presence of air currents created by the apropellers.

Other objects and advantages will appear in the subjoined detaileddescription.

The accompanying drawings illustrate the invention.

Fig. 1 is a side elevation of an aircraft constructed in accordance withthe provisions of this invention.

Fig. 2 is a plan view of Fig. l, end portions of the wing airfoil beingbroken away.

Fig. 3 is an elevation of Fig. 2 from the left thereof.

Fig. Al is an enlarged detail View of one ol the nacelle frames and itspivotal mounting.

Fig. 5` is a side elevation of one of the pivotally mounted nacelleframes.

Fig. 6 is a plan view of Fig.

`Referring to the drawings, the aircraft comprises a fuselage 7, a wingairfoil 8 connected with the fuselage, an elevator airfoil 9, a verticalfin 33, a horizontal fin Bel, and a rudder airfoil 10. In the presentinstance the aircraft is tri1notored, the nose motor being indicated at11 in the longitudinal axis of the aircraft. Outboard motors areindicated at 12, 13, on opposite sides of the longitudinal axis of theaircraft. The motors 11, 12, 13 operate, respectively, propellers 14,

`15, 16. It is to be noted that the path of rota- The outboard motors12, 13 are carried by nacelles 17, 18, respectively, and these nacellesare mounted so that they may be positioned with their longitudinal axesdirected forwardly and outwardly with respect to the longitudinal axisof the aircraft. V'llliinigli the nacelles 17, 18 may be permanentlymounted atan angle, as just mentioned, it is prenten@ that they beadjust-anymounted',

on pivots so that the motors canxbeadjusted to bring the turning axes ofthe propellers of the outboard motors either parallel to or at variousangles to the longitudinal .anis of the aircraft. The pivotalViniinting" of the nacelles maybe of anysuitable construction and,

in this instance, is as follows: Referring more particularly to Figures4, 5 and :6, the frame ofl one of the nacelles indicated at V19 andi-tis to beunderstood that the frames of the nacelles are of like'vconstruction as are also the pivotal mountings.

. Accordingly,only one of the nacelle VVframes andits vpivotalmounting-need be Vdescribed in detail. Y j, l

There is nothing unusual about theV nacelle .frame 19 Vexcepting that itis provided Y with vinwardly extending struts 20 supported by'pivotbearings 21, there preferably being two such bearings in verticalalinem'elnt. A support 22,is provided for the bearing 21. The bearingsupport 22 is carri-ed Jby struts 23,524,25, the Vstrut 28 beingsecuredfto lthe win-g airfo'il structure,and the stru-ts 24,25 beingsecured to the fuselage. -Passing .through the pivot bearings 21 andthrough flanges 26of the bearing support 22 are pivot pins v27. -Thespa-ced pivot construction is the outer end of a member 30 whichprojects laterally from thefuselage. lThe member 29 isfprovided with yaseries of holesBl which are adapted to vbe selectively engaged by a bolt32that-passes through the ears v28. The series of holes 311ies'ina-curvedpath and l -the center of-radius of said path is the axis of Ythe. pivotxpins 27.

' .The invention operates as follows:

Assumingthat' the nacelles 17 ,'18are angularlyfadjnsted so`that=theturningaxes of vthe propellers ext-end forwardly n and outwardly, as inFigure 2,l and assuming, for example, gthat, during ilight yof theaircraft, the motor 12 accidentally stops, or ispurp'o'sely stopped,thus stopping thefpropeller 15, and

` that the propeller 16 is being operated the motor 13, it will be seenthat the airship will be maintained in astraight course, when the rudderis set for straight ahead, for the reason that the slipstream from theoperating propeller 16 flows rearwardly and inwardly against'theadjacent sides of the fuselage, vertical lin and rudder airfoil. Thisslipstream tends to thrust the rear end of the aircraft to the `rightand thistendency is-exactly counteracted by the tendency of therevolving .propel- 'ler 16 to advance 'the left side'of the aircraft-faster than the right side. Thus, if one of the outboard motors shouldaccidentally stop or bepurposelyV stopped for repairs, repairs tothesame may be readily effected while the aircraft is being flown by theoperation of its other motor or motors and, while 'the repairs arev'being effected or flight is being made to a safe landing place, flyingwith the 'power unbalanced in this inanneris much safer than yif theturning axis of the outboard operating propeller were parallel to thelongitudinal axis of the aircraftand only oiie'of the outboardpropellers were operating, 'as would be the case with prior knownaircraft powered with a plurality of outboard motors.-

The' slips'tream from 'eachof the propellers flows only beneath the wingairfoil, thus avoiding reducing the'degree of partial vac uumfcreatedabove the wing airfoil by vprogriekssion ofsaid airfoil vthrough theair. y A further Vadvantage of positioning the ypropellers oftheoutboard'inotors' so that' the lslipstreains are Vdirected inwardly and4rearwardly against the sides ofthe rudder, -is that turning byfuse ofthe rudder is facilita-ted rudder airfoil makes'theaircr'aftj'moresensitive tothe rudder. l l ,I4 claim: j v.

'1. An aircraft 'comprising a wing airfoil,

ioo

. since'the 'increas'edair pressure against the -a vfuselaig'g'econnected with Vthe wing airfoil,

a rudder airfoil fadjustably connected with fthe'fuse'lage, nacellespivota'lly connected with the wing airfoil on oppositesides ofthefuselage and independently adjustable to'diiferf ent angular positionsin a horizontal plane, means to independently secure the lnacelles inthe'p'ositi'ons to'whic'h they are adjusted, motors mounted on thenacelles, Vpropellers Ymounted on and operated by ysaid motors, and avertical'lin connected with the fuselage and ,extending along the centerline `thereof toreceive the thrust of there'arwardly 'and VinwardlyVRowing slip'stream from V'one of the prop'ellers when the motordriving" the other propeller is inactive.

2. Anaircraft comprising a wing airfoil, a fuselage connected with thewing airfoil, bearing supports, struts connecting' the bearing supportswith the wing 'airfoil,'other, struts v'connecting the bearing supportswith the fuselage, bearings' carried'by'the bearing supports,nacellessu'pportedby the bearings, a means to releasably'secure each'offthenacelles in different positions relative to its associatedbearing support, a motor mounted on each nacelle, and a propellercarried and operated by each motor.

'5 3. An aircraft comprising a wing airfoil, a fuselage connected withthe Wing airfoil, bearing supports, struts connectinv' the bearingsupports with the Wing air'foil, other struts connecting the bearingsupports with the fuselage, vertically positioned bearings carried bythe bearing supports, nacelles supported by the bearings to swinghorizontally into different positions, a means to releasably secure eachof the nacelles in the di Herent po sitions, a motel' mounted on eac-l1nacelle, and

a propeller carried and operated by each m0- tor.

4. An aircraft comprising a Wing airfoil, afuselage connected with theWing arfoil,

bearing supports, struts connecting the bearing supports With the WingVairfoil, other struts connecting the bearing supports With the fuselage,bearings carried by the bearing supports, nacelles provided Withinwardly extending struts supported by the bearings, a

means to releasably secure each of the nacelles in different positionsrelative to its associated bearing support, a motor mounted on eachnacelle, and a propeller carried and 3U operated by each motor.

Signed at Los Angeles, California, this 8th day of December, 1928.

ALBIN K. PETERSON.

